Lifting device



Dec- 8, 1964 l. DE WITT STEED 3,160,228

LIFTING DEVICE Filed Feb. 6, 1962 3 Sheets-Shea?l 1 f27 Inl l I ,53 |y hl o IVENTOR IRAN DewlTT STEED BY 717 /bglacee/IH ATTORNEYJ Dec. 8, 1964 l. DE WITT STEED LIFTING DEVICE 3 Sheets-Sheet 2 Filed Feb. 6, 1962 FIG.. 4

INVENTOR IRAN De WITT STEED Dec. 8, 1964 l. DE WITT sTEED 3,160,228

LIFTING DEVICE Filed Feb. 6, 1962 3 Sheets-Sheet 3 INVENTOR IRAN DeWITT STEED United States Patent O 3,160,228 LIFTING DEVICE Iran De Witt Steed, Rte. 9, Springfield, Mo. Filed Feb. 6, 1962, Ser. No. 171,506 2 Claims. (Cl. 1232-148) This invention relates to lifting devices in general and more particularly to lifting devices motor driven. Most lifting devices require a great deal of effort on the part of the operator, complicated pulley equipment or a powerful motor to raise a load of any consequence; with this lifting device, a large load may be lifted with a very small motor. Then, too, there is a certain amount of danger connected with most devices that raise a little at a time; an object of this lifting device is to eliminate the danger of a fall through mechanical failure. A further object is to supply a raising vehicle that will lower quickly, efciently and safely, unlike contrivances which lower as a jack. Still another object is to do away with old-fashioned metal scaifolds which are slow, heavy and cumbersome and which must have material carried up to them at their stationary height either by a man walking up a ladder or some mechanical hoist. With my lifting device, a man may lower himself to his material of brick, mortar, lumber, stucco, paint, etc., load an amount and move himself immediately back up to several feet of height by the iiip of a switch. Along this same line: Three or four of these lifts may be tied to a common switch and with run boards or platforms from one to the other, a series of long, evenly raising scaffolds may be set up.

Installed in basements, they may be used as efficient, inexpensive elevators in one and two story homes and office buildings. They may even be used in staggered series to hold up the form bed for a concrete and steel re-inforced roof or oor until cured.

Further objects of the invention and novel features of its construction will be apparent from the following specification when considered together with the accompanying drawing, in which:

FIGURE 1 is a view from above of the lifting device;

FIGURE 2 is a fragmentary view, showing from the side the close relationship between power and lift;

FIGURE 3 is an end View;

FIGURE 4 shows the lifting device depressed or brought down to its low point;

FIGURE 5 shows the lifting device raised to almost its fullest extent.

In FIGURE 2, a motor support 9 holds electric motor 10 which actuates motor pulley wheel 11 turning threaded shaft 12, which has right hand threads on one end and left hand threads on the other, by means of belt 13 rolling on shaft pulley wheel 14, held in place, as shown in FIGURE 5, by set screw 15. Again in FIGURE 2, threaded shaft 12, anchored to table 16 by bearing pillow blocks 17 and 18, shown in FIGURE 1, turns in puller nuts 19 and 20, which have puller arms 21, 22, 23 and 24 fastened to them, one on either side of each nut and extending outward to telescoping sleeves 25, 26, 27 and 28, t'o which they are fastened at points 29, 30, 31 and 32. Also threaded shaft 12 turns in brace nuts 33 and 34 which are a short distance away from puller nuts 19 and 20 and have brace arms 35, 36, 37 and 38 aixed to said brace nuts 33 and 34, and which are anchored to puller arms 21, 22, 23 and 24 at puller arm-brace joints 39, 40, 41 and 42. In FIGURE 5, telescoping sleeve lips 43, 44, 45 and 46 atop telescoping sleeves 25, 26, 27 and 28 are fastened with bolts 47 and 43, shown in FIGURE 2, bolt 49, shown in FIGURE 5, and bolt Sil, shown in FIGURE 3, to braced X frames a, b, c and d, shown in FIGURE 5. Telescoping sleeves 25, 26, 27 and 28 move backward and 3,160,228 Patented Dec. 8, 1964 forward over telescoped shafts 51, 52, 53 and. 54, said telescoped shafts anchored to table 16 by U bolts 55, 55a, 56, 56a, 57, 57a, 58 and 58a shown in FIGURE 1. Separating telescoped shafts 51, 52, 53 and 54 from table ldarge shinis e, f, g, h, j, k, l and m, shown in FIGURES 5 an From the above construction, as shown in FIGURE 5, it can be seen that when switch box lever 59 on forward and reverse switch box 60, wired to electric motor 10 by switch wire 61 and conducting cable 62, is turned to forward position, the electric motor 1t) turns threaded shaft 12, which, turning in puller nuts 19 and 20 and brace nuts 33 and 34 causes them to move toward each other, which, in turn, causes puller arms 21, 22, 23 and 24, and brace arms 35, 36, 37 and 38 also to move toward each other, thus moving the bases of the braced X frames a, b, c, and d toward each other causing platform 63, whose four corners are fastened t'o said X frames by hinges 63a, 63b, 63C and 63d, and whose safety is aided by railing 64, to be raised several feet in height. Upper progress of platform 63 may be stopped automatically by limit switch 65. Platform 63 is lowered by turning switch box lever 59 on switch box 60 to a reverse position. The reverse action causes X frames a, b, c and d to move in an opposite direction by action on them of puller nuts 19 and 20, brace nuts 33 and 34, puller arms 21, 22, 23 and 24, and brace arms 35, 36, 37 and 38. X frames a, b, c and d are stopped in descent by limit switch 66.

For use of the lift on uneven terrain, FIGURES 2, 3 and 4 show adjustable legs 67, 68, 69 and 70; and in the same figures, for ease of movement from place to place, locking rollers 71, 72, 73 and '74 are shown fastened to adjustable legs 67, 68, 69 and 70.

Speed of the device, either upward or downward, is governed by the size of the pulley wheel 11 on electric motor 1G and shaft pulley wheel 14. For normal speed, up and down, a 2 inch motor pulley wheel and a 10 inch shaft pulley wheel work well. However, for abnormally slow speeds and much greater power, an electric motor geared to an extremely slow speed should be used.

I claim:

l. A lifting device of the character described comprising, in combination,

a generally rectangular table member,

said table member being adapted .to be mounted on adjustable legs having locking rollers thereon whereby it may be maintained level and stationary on an uneven surface,

slide-supporting shaft members mounted on the upper surface of said table and adjacent each corner portion thereof, said slide-supporting shaft members being. disposed in parallelism to each other and positioned in a common plane parallel to the upper surface of said table member,

a screw shaft having reversely threaded portions at each end thereof disposed intermediate of and parallel to said slide-supporting shaft members and eX- tending substantially the length of said table member,

bearing pillow block means for rotatably mounting said screw shaft in the common plane of said slidesupporting shaft members,

a pair of nut members axially spaced from each yother on each end of said screw shaft and threadedly engaging the reversely threaded portion at each respective end of said screw shaft,

a load-bearing sleeve comprising a slide member coaxially engaging each slide-supporting shaft member for sliding movement therealong and positioned abreast of `one of each pair of said nut members,

a pantograph type vertically movable platform having leg' members at its lower end pivotally secured to said load-bearing slide members,

linkage means connecting each pair of spaced nut members at each end of said screw shaft with the pair of load-bearing slide members positioned abreast of each pair of said spaced nut members and forming a truss-like connection therebetween,

d rive means on said screw shaft positioned intermediate the pairs of said spaced nut members threadedly mounted thereon,

said bearing pillow block means for said screw shaft being located solely intermediate said drive means and said reversely threaded portions on said screw shaft,

motor means mounted beneath said table and having means engaging said screw shaft drive means through an opening in said Itable member,

and means for controlling said motor means for rotating said screw shaft in opposite directions for raising and lowering the platform.

2. A lifting device as defined in claim 1 wherein said means for controlling said motor includes:

'References Cited in the tile of this patent UNITED STATES PATENTS 512,052 McHenry Ian. 2, 1894 722,166 Taft Mar. 3, 1903 797,077 Shaw Aug. 15, 1905 2,062,473 Norton Dec. 1, 1936 y2,206,788 Meacham July 2, 1940 2,818,567 Oliver Jan. 7, 1958 

1. A LIFTING DEVICE OF THE CHARACTER DESCRIBED COMPRISING, IN COMBINATION, A GENERALLY RECTANGULAR TABLE MEMBER, SAID TABLE MEMBER BEING ADAPTED TO BE MOUNTED ON ADJUSTABLE LEGS HAVING LOCKING ROLLERS THEREON WHEREBY IT MAY BE MAINTAINED LEVEL AND STATIONARY ON AN UNEVEN SURFACE, SLIDE-SUPPORTING SHAFT MEMBERS MOUNTED ON THE UPPER SURFACE OF SAID TABLE AND ADJACENT EACH CORNER PORTION THEREOF, SAID SLIDE-SUPPORTING SHAFT MEMBERS BEING DISPOSED IN PARALLELISM TO EACH OTHER AND POSITIONED IN A COMMON PLANE PARALLEL TO THE UPPER SURFACE OF SAID TABLE MEMBER, A SCREW SHAFT HAVING REVERSELY THREADED PORTIONS AT EACH END THEREOF DISPOSED INTERMEDIATE OF AND PARALLEL TO SAID SLIDE-SUPPORTING SHAFT MEMBERS AND EXTENDING SUBSTANTIALLY THE LENGTH OF SAID TABLE MEMBER, BEARING PILLOW BLOCK MEANS FOR ROTATABLY MOUNTING SAID SCREW SHAFT IN THE COMMON PLANE OF SAID SLIDESUPPORTING SHAFT MEMBERS, A PAIR OF NUT MEMBERS AXIALLY SPACED FROM EACH OTHER ON EACH END OF SAID SCREW SHAFT AND THREADEDLY ENGAGING THE REVERSELY THREADED PORTION AT EACH RESPECTIVE END OF SAID SCREW SHAFT, A LOAD-BEARING SLEEVE COMPRISING A SLIDE MEMBER COAXIALLY ENGAGING EACH SLIDE-SUPPORTING SHAFT MEMBER FOR SLIDING MOVEMENT THEREALONG AND POSITIONED ABREAST OF ONE OF EACH PAIR OF SAID NUT MEMBERS, A PANTOGRAPH TYPE VERTICALLY MOVABLE PLATFORM HAVING LEG MEMBERS AT ITS LOWER END PIVOTALLY SECURED TO SAID LOAD-BEARING SLIDE MEMBERS, LINKAGE MEANS CONNECTING EACH PAIR OF SPACED NUT MEMBERS AT EACH END OF SAID SCREW SHAFT WITH THE PAIR OF LOAD-BEARING SLIDE MEMBERS POSITIONED ABREAST OF EACH PAIR OF SAID SPACED NUT MEMBERS AND FORMING A TRUSS-LIKE CONNECTION THEREBETWEEN, DRIVE MEANS ON SAID SCREW SHAFT POSITIONED INTERMEDIATE THE PAIRS OF SAID SPACED NUT MEMBERS THREADEDLY MOUNTED THEREON, SAID BEARING PILLOW BLOCK MEANS FOR SAID SCREW SHAFT BEING LOCATED SOLELY INTERMEDIATE SAID DRIVE MEANS AND SAID REVERSELY THREADED PORTIONS ON SAID SCREW SHAFT, MOTOR MEANS MOUNTED BENEATH SAID TABLE AND HAVING MEANS ENGAGING SAID SCREW SHAFT DRIVE MEANS THROUGH AN OPENING IN SAID TABLE MEMBER, AND MEANS FOR CONTROLLING SAID MOTOR MEANS FOR ROTATING SAID SCREW SHAFT IN OPPOSITE DIRECTIONS FOR RAISING AND LOWERING THE PLATFORM. 